duplicate-data

问题 I have a table that contains unfortuantely bad data and I'm trying to filter some out. I am sure that the LName, FName combonation is unique since the data set is small enough to verify. LName, FName, Email ----- ----- ----- Smith Bob bsmith@example.com Smith Bob NULL Doe Jane NULL White Don dwhite@example.com I would like to have the query results bring back the "duplicate" record that does not have a NULL email, yet still bring back a NULL Email when there is not a duplicate. E.g. Smith Bob

问题 I have got a simple contacts database but I'm having problems with users entering in duplicate data. I have implemented a simple data comparison but unfortunately the duplicated data that is being entered is not exactly the same. For example, names are incorrectly spelled or one person will put in 'Bill Smith' and another will put in 'William Smith' for the same person. So is there some sort of algorithm that can give a percentage for how similar an entry is to another? 回答1: So is there some

问题 Is there a way to insert into an SQL database where the whole record is unique? I know you can make primary keys and unique columns, but that is not what I want. What is the best way of doing this without overloading the database? I have seen a sort of subquery where you use "WHERE NOT EXISTS ()" I just want to know the most efficient way of inserting a record so that there are no duplicates of the EXACT same record. Thank you in advance! 回答1: You know how to make a unique index on a column.

问题 It was my impression that using #import would only import a file once per build, yet after trying to define a variable in a header, and then importing that header in two different source files, I get a duplicate symbol linker error for the variable. How is this possible? 回答1: #import makes header to be included once per file , but not per build. So your variable is defined in every file where you import your header and as global variable is visible by default in whole project you get linker

问题 Coming from Eclipse and having been used to duplicate lines all the time, it's pretty strange finding out that Xcode has no such function. Or does it? I know it's possible to change the system wide keybindings but that's not what I'm after. 回答1: The whole point is NOT to use the Cmd-C / Cmd-V shortcuts. I have the same issue coming from IntelliJ, and being able to just duplicate lines with Cmd-D and delete them with Cmd-Y is a big time saver. It's been bugging me ever since. However, it looks

问题 How do you count duplicates in a ruby array? For example, if my array had three a's, how could I count that 回答1: This will yield the duplicate elements as a hash with the number of occurences for each duplicate item. Let the code speak: #!/usr/bin/env ruby class Array # monkey-patched version def dup_hash inject(Hash.new(0)) { |h,e| h[e] += 1; h }.select { |k,v| v > 1 }.inject({}) { |r, e| r[e.first] = e.last; r } end end # unmonkeey'd def dup_hash(ary) ary.inject(Hash.new(0)) { |h,e| h[e] +=

问题 What is the best way to remove duplicate entries from a Data Table? 回答1: Remove Duplicates public DataTable RemoveDuplicateRows(DataTable dTable, string colName) { Hashtable hTable = new Hashtable(); ArrayList duplicateList = new ArrayList(); //Add list of all the unique item value to hashtable, which stores combination of key, value pair. //And add duplicate item value in arraylist. foreach (DataRow drow in dTable.Rows) { if (hTable.Contains(drow[colName])) duplicateList.Add(drow); else

问题 I am creating an app in which people give scores to other persons. For that, I want to insert names of some person (say 5) to a database during installation of the app. Now the when I run the app first time everything goes fine. But when I run it second time, the data are inserted again making it 10, i.e. duplicate data. The problem is whenever I run this activity, it adds the data. What is the solution to this problem? Here's my code: @TargetApi(Build.VERSION_CODES.HONEYCOMB) public class

问题 I have a array of associative arrays aa[] = ('Tires'=>100, 'Oil'=>10, 'Spark Plugs'=>4 ); aa[] = ('Tires'=>454, 'Oil'=>43, 'Spark Plugs'=>3 ); aa[] = ('Tires'=>34, 'Oil'=>55, 'Spark Plugs'=>44 ); aa[] = ('Tires'=>454, 'Oil'=>43, 'Spark Plugs'=>45 ); aa[] = ('Tires'=>34, 'Oil'=>55, 'Spark Plugs'=>433 ); aa[] = ('Tires'=>23, 'Oil'=>33, 'Spark Plugs'=>44 ); Two Questions How can I remove duplicates according tot he field 'Oil' is there a array_unique which I can provide a callback which acts as

问题 I have this excel problem. I am trying to find matching text between 2 columns and then remove the matched text. Example Column 1: John Romeo Column 2: John Romeo 16 Smith Street Results: 16 Smith Street The Results column is the text that I want. 回答1: Here's a custom function called WORDDIF that may do what you want. To install the custom function in Windows ... Alt+F11 to open the VBA Editor From the VBA menu, select Insert -> Module To install the custom function in OS X ... Go to Tools ->